1. Field of the Invention
The present disclosure relates generally to down-hole operations related to oil and gas exploration, drilling and production. More particularly, embodiments of the disclosure relate to systems and methods that employ hydraulic fluid flow through a turbine for down-hole electrical power generation and tool activation.
2. Background
Modern hydrocarbon drilling and production operations often require electrical power for equipment down-hole. For example, electrical power may be used down-hole for a number of applications, including well logging, formation evaluation, and telemetry. Both wellbore logging and formation evaluation tools often include active sensors that use power to obtain information. This information typically includes various characteristics and parameters of geologic formations traversed by the wellbore, data relating to the size and configuration of the wellbore itself, pressures and temperatures of ambient down-hole fluids, and other down-hole parameters. Telemetry equipment commonly utilizes electrical power to relay data acquired from various logging sensors or other tools to the surface.
One approach to generating electrical power down-hole utilizes the circulation of drilling fluid (or “mud”) through a turbine to generate mechanical rotary motion in a turbine shaft, spinning a down-hole generator. Often, the turbine is constrained within a predefined speed range to prevent the generator from rotating too fast and thereby producing an overvoltage that may damage electronic equipment and to prevent the generator from operating too slowly to produce sufficient electrical power for the connected electronics. Often, the rotary motion in the turbine shaft is also employed to operate an actuator of another down-hole tool such as a hydraulic pump, a cutting tool, a vibratory tool, a valve mechanism or similar tool. At least one problem with this approach is that the actuator of these tools may have speed limitations that frustrate the efficiency of the generator.